Multicasting data offers efficient utilization of network resources to deliver data to multiple users. For example, telecommunications service providers offer unified data, voice and video services to the customers over their Digital Subscriber Line (DSL) networks. A TV program is transmitted in IP multicast over the DSL network to the media gateways at the customer homes. The program data can then be redistributed to the set-top boxes, IP TV receivers or mobile devices (called receivers in this area of technology) over wireless local area networks (WLANs) in customers' homes. However, the transmission of multicast data packets is not as reliable as the transmission of unicast data packets in a WLAN. The techniques for reliable transmission, such as adaptation of modulation and channel coding schemes and retransmissions of lost packets are only used for unicast data traffic by the WLAN physical and data link layers. That is, the WLAN can much more reliably transmit data packets with unicast destination addresses than data packets with a multicast address.
Application layer error control techniques such as forward error correction (FEC) and resilience video coding can improve the reliability of multicast video transmission. However, these techniques introduce high overhead such that the bandwidth efficiency is reduced. Furthermore, for multicast transmissions, there may be multiple receivers and each receiver may incur different radio link qualities. It is difficult to satisfy the requirements of all the receivers.
Some video/audio streaming server software can convert a multicast stream to multiple unicast streams. However, the streaming server software runs on a computer and only binds one IP interface with the host IP address. The server software receives the multicast stream and sends out the unicast streams over the same interface. If the same video stream is sent from the streaming server to multiple homes or multiple receivers in a home in unicast, it would consume increased network resources such as bandwidth in the wired DSL network.